The code $ENV{'DBISERVER'} retrieves the DBISERVER environment variable, if the '-server' parameter is not specified by the caller. You could override the default server string when you create the object -

my $obj = CLASSNAME->new(
              -server => "mysql:server=xxxx;database=xxxx",
              -user => "xxxx",
              -pass => "xxxx" );
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Where CLASSNAME is the name of your class module. I have written a demo below on using mysql via DBI:

#!/usr/bin/perl -w
use strict;
use DBI;
use DBD::mysql;

my $dbh = DBI->connect("dbi:mysql:server=somedomain.com;database=main_
+DB", "USER","PASSWD")
        or die "Failed to connect to the database!";

my $sth = $dbh->prepare( qq{ SQL } );
$sth->execute();

my @column_headings = @{$sth->{NAME}};

while (my @row = $sth->fetchrow())
{
    # Data elements $row[0] ... $row[$#row-1]
    ...
}

$sth->finish;
$dbh->disconnect;
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